Liquid hydrocarbon containing alkali metal salts of diarylcarbamates as antiknock agents

ABSTRACT

Liquid hydrocarbon fuel compositions are provided containing antiknock quantities of alkali metal salts of diarylcarbamates.

United States Patent Heiba et a1.

[ NOV. 13, 1973 Filed: Sept. 28, 1972 Appl. No.: 293,218

US. Cl 44/71, 44/75, 252/386 Int. Cl C10] 1/22 Field of Search 44/71, 75, 68;

References Cited UNITED STATES PATENTS [/1971 Abowd, Jr. 44/71 3,226,427 12/1965 Dunbar 44/71 2,842,433 7/1958 Newman et al.... 2,728,648 12/1955 I-Iirschler et a1. 44/71 2,637,698 5/1953 Kirshenbaum Primary Examiner-Daniel E. Wyman Assistant Examiner-Y. H. Smith Att0rneyAndrew L. Gaboriault et a1.

[57] ABSTRACT Liquid hydrocarbon fuel compositions are provided containing antiknock quantities of alkali metal salts of diarylcarbamates.

11 Claims, No Drawings LIQUID HYDROCARBON CONTAINING ALKALI METAL SALTS OF DIARYLCARBAMATES AS ANTIKNOCK AGENTS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to liquid hydrocarbon fuel composition having improved antiknock properties. In one of its aspects, the invention relates more particularly to liquid hydrocarbon fuel compositions intended for use in internal combustion engines containing improved and effective antiknock agents.

2. Description of the Prior Art Various antiknock agents have, heretofore, been suggested and employed. for use in liquid hydrocarbon fuels, particularly in fuels employed in internal combustion engines. In such engines, it is highly desirable, from a standpoint of economics, that combustion of the fuel occurs at relatively high compression ratios. Such high compression ratios concomitantly necessitate the use of fuels having'relatively high octane numbers to insure knock-free operation.

The most widely known antiknock agents include: aniline and alkyl derivatives thereof such as N- methylaniline; N-ethylaniline and N, N- dimethylaniline; phenylenediamines; nitriles, such as proprionitrile; tertiary alkyl ethers; tetramethyl lead; and tetraethyl lead. In general, however, none of these antiknock additives have proved to be entirely satisfactory in effectively raising the octane number of the fuel without also exhibiting other undesirable properties of varying importance.

SUMMARY OF THE INVENTION In accordance with the present invention, new and improved liquid hydrocarbon fuel compositions are provided containing an antiknock quantity of alkali metal salts of diarylcarbamates. Representative of these antiknock compounds are sodium salts of diphenyl carbamates, lithium salts of diphenyl carbamates, sodium salts of diphenyloctyl carbamates, and 'lithium salts of diphenyloctyl carbamates. Specific representative examples of the aforementioned alkali metalsalts of diarylcarbamates include sodium N, N-diphenyl car bamate, sodium methylphenyl carbamate, sodium dioctyldiphenyl carbamate and lithium dioctyldiphenyl carbamate. In general, the aforementioned antiknock additives of the present invention are employed in amounts from about 0.1 to about percent, and preferably from about 0.1 to about 2 percent, by weight, of the total weight of the fuel composition.

DESCRIPTION OF SPECIFIC EMBODIMENTS The antiknock agents of the present invention are prepared, in general, as more fully hereinafter described, by reacting a diarylamine with an alkali metal or alkali metal compound to produce an alkali metal salt of the corresponding diarylamine. Reacting the alkali metal salt of the diarylamine, thus produced with carbon dioxide produces the corresponding alkali metal salt of the diarylcarbamate. I

The following examples and comparative data will serve to illustrate the preparation of the antiknock compounds of the present invention and their efficacy in improving the octane number of liquid hydrocarbon fuels. It will be understood, however, that it is not intended that the invention be limited to the particular 2 antiknock compounds or the particular liquid hydrocarbon fuels containing these compounds,-as described. Various modifications of these antiknock agents and liquid hydrocarbon fuels can be employed,

as will readily be apparent to those skilled in the art.

The antiknock compounds of the present invention have the general formula:

in which R to R, is hydrogen, alkyl having from 1 to 12 carbon atoms, alkoxy, halogen, nitro or amino and M is an alkali metal.

EXAMPLE 1 Preparation of Sodium N, N-diphenyl carbamate Sodium metal (2.3 gm., 0.1 mole) was added portionwise to a solution of 0.2 gm. ferric nitrate in cc. liquid ammonia. To the gray solution of sodium amide thus formed, a solution of 16.9 gm. (0.1 mole) diphenylamine in 150 cc. tetrahydrofurane was added. The reaction mixture was stirred at room temperature until all of the liquid ammonia had evaporated off, and then gaseous carbon dioxide was bubbled through for 2 hours. The reaction mixture was then filtered and the tetrahydrofurane was evaporated off under reduced pressure to yield the desired sodium N, N-diphenyl carbamate as a white solid.

Y EXAMPLE 2 Preparation of Sodium Methylphenyl Carbamate The. preparation of this carbamate was identical to that in Example 1, except that 107 gm. N- methylaniline wasused instead of diphenylamine.

EXAMPLE 3 Preparation of Sodium Dioctylphenyl Carbamate The preparation of this carbamate was identical to that of Example 1, except that 39.4 gm. of 4,4'-dioctylphenylamine was used in place of the diphenylamine.

EXAMPLE 4 Preparation of Lithium Dioctylphenyl Carbamate To a solution of 39.4 gm. 4,4'-dioctyldiphenylamine in 200 cc. tetrahydrofurane was added a solution of 0.1 mole n-butyl lithium in hexane. After stirring at room temperature for a half hour, carbon dioxide was bubbled through the solution for 2 hours. Evaporation of the solvents under reduced pressure afforded the desired lithium dioctylphenyl carbamate.

EXAMPLE 5 Preparation of Lithium Diphenyl Carbamate The preparation of this carbamate was identical to that of Example 4, except that 16.9 gm. of diphenylamine was used in place of the 4,4'-dioctyldiphenylamine.

In the examples and comparative data of the following table are shown the results obtained from a determination of the Research Octane Numbers (RON), according to ASTM D-2699, of fuel blends containing the compounds described in the foregoing examples. The base fuel used had the following characteristics: percent boiled to 122F., 50 percent to 223'F. and 90 percent to 345F. with anend point of 403F. It contained 33 percent aromatics, 10 percent olefins and 57 percent saturates. It was composed of 40 percent 100 reformate, 40 percent TCC, 10 percent 100 straight run, 6 percent light alkylate, and 4 percent butane.

Wei t o RON of RON of RON Example Compound Base Blend Increase fuel The efficacy of the antiknock compounds of the present invention for improving the antiknock properties of liquid hydrocarbon fuels will be apparent from the foregoing examples and comparative data. It will be understood that these compounds may be advantageously employed in any liquid hydrocarbon fuel composition which is suitable for use in a combustion engine, regardless of the purpose for which the engine is designed.

The antiknock effect of the compounds of the present invention is independent of other antiknock agents that may be concomitantly emloyed. Thus, the compounds of the present invention will increase the antiknock ratings of liquid hydrocarbon fuels even though other antiknock agents may also be present. It will also be understood that other additives intended for the purpose of imparting other improving properties to the fuel may be employed in combination with the present antiknock compounds. Hence, metal deactivators, antioxidants, anti-rust, anti-stalling and ignition control compounds may also be employed in these fuels.

Although the present invention has been described with certain specific and preferred embodiments, for purposes of illustration, it will be understood that various modifications and adaptations thereof, which will be obvious to those skilled in the art, may be made without departing from the spirit of the invention.

We claim:

l. A liquid hydrocarbon fuel composition containing an antiknock quantity of an alkali metal salt of a diarylcarbamate having the formula:

in which R to R is hydrogen, alkyl having from 1 to 12 carbon atoms, and M is an alkali metal.

2. The composition of claim 1 wherein said antiknock compound comprises a sodium salt of a diphenyl carbamate.

3. The composition of claim 1 wherein said antiknock compound comprises a lithium salt of a diphenyl carbamate.

4. The composition of claim 1 wherein said antiknock compound comprises a sodium salt of a diphenyloctyl carbamate.

5. The composition of claim 1 wherein said antiknock compound comprises a lithium salt of a diphenyloctyl carbamate.

6. The composition of claim 1 wherein said antiknock compound comprises sodium N, N-diphenyl carbamate.

7. The composition of claim 1 wherein said antiknock compound comprises sodium methylphenyl carbamate.

8. The composition of claim 1 wherein said antiknock compound comprises sodium dioctylphenyl carbamate.

9. The composition of claim 1 wherein said antiknock compound comprises lithium dioctylphenyl carbamate.

10. The composition of claim 1 containing from about 0.1 to about 5 percent, by weight, of the antiknock compound.

11. The composition of claim 1 containing from about 0.1 to about 2 percent, by weight, of the antiknock compound.

i233? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Pltcnt No. 3,77 ,979 Du November 13, 1973 immorm EL-AHMADI I. HEIBA and STAMOULIS STOURNAS It is certified that error appears in the above-identified patent and that aid Latter: Patent are hereby corrected as shown below:

First page, after "Inventors: N. J. insert --Assignors to Mobil Oil Corporation". A

First page, in the Title After "HYDROCARBON" insert "F LTELS o Column 1, line 1, in the Title After "HYDROCARBON" insert FUELS-7. 1 v A Column 3, line 3%, "emloyed should read --employ,ed.-

Signed and sealed this 30th day of April 'lSVZll.

(SEAL) Attest:

EDWARD DLFLETCHERJE-i. O. MARSHALL DAIJN Attesting Officer Commissioner of Patents 

2. The composition of claim 1 wherein said antiknock compound comprises a sodium salt of a diphenyl carbamate.
 3. The composition of claim 1 wherein said antiknock compound comprises a lithium salt of a diphenyl carbamate.
 4. The composition of claim 1 wherein said antiknock compound comprises a sodium salt of a diphenyloctyl carbamate.
 5. The composition of claim 1 wherein said antiknock compound comprises a lithium salt of a diphenyloctyl carbamate.
 6. The composition of claim 1 wherein said antiknock compound comprises sodium N, N-diphenyl carbamate.
 7. The composition of claim 1 wherein said antiknock compound comprises sodium methylphenyl carbamate.
 8. The composition of claim 1 wherein said antiknock compound comprises sodium dioctylphenyl carbamate.
 9. The composition of claim 1 wherein said antiknock compound comprises lithium dioctylphenyl carbamate.
 10. The composition of claim 1 containing from about 0.1 to about 5 percent, by weight, of the antiknock compound.
 11. The composition of claim 1 containing from about 0.1 to about 2 percent, by weight, of the antiknock compound. 